1. Field of the Invention
Embodiments of the disclosed invention relate generally to a coating agent, in particular a sealing coating agent suitable for use with composite building materials comprising cementitious materials, gypsum, or other suitable inorganic building materials such as those containing cellulose, glass, steel or polymeric fibers.
2. Description of the Related Art
In the construction industry, building materials are often prefinished with coating systems or laminates prior to sale and installation. Economies of scale typically permit a manufacturer to coat or laminate materials at a lower cost and to a higher standard than an end user of unfinished material. A manufacturer therefore has complete control over the quality and consistency of the prefinished products leaving the factory. This ensures that each prefinished product has a predictable service lifetime. Such materials are easily installed and do not require subsequent finishing. Thus prefinished siding planks and panels are particularly popular due to reduced labor costs and time saved during installation.
Different types of sealing agents have been developed to seal the cementitious products. Generally, it is very difficult to apply a paint coat directly onto a sealing agent, as a sealing agent does not provide sufficient adhesion for direct application of a paint coat. Furthermore, in practice, transparent sealing agents are often applied to the cementitious product prior to application of the primer coat or layer. It is sometimes difficult to visually ensure that the sealing agent has adequate coverage on the product prior to application of the primer coat or layer. Consequently if the sealing agent or sealer coat or layer is not applied correctly the performance of further layers or coats will be affected. Furthermore, it is thought that some clear sealing agents are potentially susceptible to degradation by ultra-violet (UV) light. Accordingly, such sealing agents will not provide an adequate adhesion surface for the priming agent or further coats on cementitious materials.